My guess is that the video clip was from either GWB's first election to the Texas Governorship (when he cleaned Ann Richard's clock), or from his re-election. If I were Karl Rove, I would be sending that clip to each and every member of the Kerry team on November 3rd, with a reminder:
"Now, you're going to have to deal with this man for FOUR MORE YEARS! (ahem)...and WITHOUT LUBE!"
Excellent idea!